I have Graphics^ g created on a PictureBox. I can draw on it inside events like MyForm_Load, Button_Click, but not in Timer_Tick. It doesn't draw anything:
System::Void timer1_Tick(...) {
g->Clear(Color::White);
Pen^ pen = gcnew Pen(Color::Black, 1);
g->DrawLine(pen, 10, 10, 30, 50); // of course values may change
}
How to solve the problem?
To show the drawing immediately, refresh an object which drawing is created on. For example, if drawing was created like g = Graphics::FromImage(pictureBox1->Image); use pictureBox1->Refresh();
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i am trying to use glass magnifier on PictureEdit(devexpress) control in windows form
we have set PictureEdit.SizeMode =Squeeze . its important. in our application i am already using Squeeze size mode.
i am getting problem of calculation of mouse location , for draw rect image onto enalged panel.
here is code of PartialMag_Paint event of enalaged panel. in which we show zoomed imaged of mouse pointed area
int srcx = (PartailMagImageView.Location.X + PartailMagImageView.Width / 2);
int srcy = (PartailMagImageView.Location.Y + PartailMagImageView.Height / 2);
e.Graphics.DrawImage(this.Image
, new System.Drawing.Rectangle(0, 0, PartailMagImageView.Width, PartailMagImageView.Height)
, new System.Drawing.Rectangle(srcx - ZoomOutRate / 2, srcy - ZoomOutRate / 2, ZoomOutRate, ZoomOutRate)
, GraphicsUnit.Pixel);
Pen mypen = new Pen(Color.Black, 7);
e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
e.Graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
e.Graphics.DrawEllipse(mypen, 0, 0, PartailMagImageView.Width - 7, PartailMagImageView.Height - 7);
if any one need to see complete code sample. i am attaching sample in dropbox link
https://www.dropbox.com/s/mogmshuiimtvhk7/ImageMagnifyingWindowsForm.zip?dl=0
PictureEdit has the ViewportToImage and ImageToViewport methods allowing you to convert viewport coordinates to the source image coordinates and vice versa.
This is a follow-up of my question: Make the cursor a self-drawn image.
I have a paint a picture application. The latest working version can be found here: https://knowledgeablekangaroo.github.io/paint-a-picture-backup/, where the code can be found in F12 > Sources > paint-a-picture.js.
The user can choose a color, set the background, set the thickness, shape, and opacity. There is also an eraser functionality. I want there to be a better user experience, so I am trying to draw the eraser below as the cursor. If the cursor doesn't work, I need something that doesn't smear.
The way I have programmed it, anywhere inside the "paint area" (above control center and below pallete) will smear - the background() is outside the draw.
var pg = createGraphics(pgDimensions.w, pgDimensions.h, JAVA2D);
pg.beginDraw();
pg.fill(255, 200, 255);
pg.strokeWeight(2);
pg.rect(0, 0, pgDimensions.w, pgDimensions.h);
pg.fill(0);
pg.textAlign(CENTER, CENTER);
pg.text("ERASER", pgDimensions.w / 2, pgDimensions.h / 2);
pg.endDraw();
I used the createGraphics() function to create a PGraphics Object. The point is to show the eraser while This shows the eraser I have drawn in the pGraphic above.
In the drawBrush() function, I make this an image.
var drawBrush = function() {
fill(currentColor);
noStroke();
shapes.forEach(function (element, index) {
if (pshape == index) {
element.brush();
}
});
if (C === bgColor) {
image(pg, mouseX - pgDimensions.w / 2, mouseY - pgDimensions.h / 2);
}
};
Research
This best describes my problem
After you have a graphics stored in your pg variable, you can draw that using the image() function:
image(pg, mouseX, mouseY);
Here's a small example that demonstrates what I'm talking about:
var pg;
function setup() {
createCanvas(400, 400);
pg = createGraphics(100, 100);
pg.ellipse(50, 50, 100, 100);
}
function draw() {
background(220);
image(pg, mouseX, mouseY);
}
I have a canvas with a background image:
var bi = new BitmapImage(new Uri(imgLocFull));
var ib = new ImageBrush(bi) {Stretch = Stretch.UniformToFill};
MyCanvas.Background = ib;
I am overlaying various shapes on the image, and want the position of the shapes relative to the background image to be fixed.
If my application window is resized, the amount of the image that is cropped, horizontally and vertically, changes, and when my shapes are redrawn, they do not appear in the same position on the background image.
How can I determine how much of the image has been cropped (to apply an adjustment factor to the overlaid objects' positions?) Or is there a better way of fixing the location of a shape relative to the background image?
Here is my present drawing code:
var l = new Ellipse();
var scb = new SolidColorBrush();
scb.Color = Color.FromRgb(rCol, gCol, bCol);
l.Fill = scb;
l.StrokeThickness = 0;
l.Width = 3;
l.Height = 3;
Canvas.SetBottom(l, point.Y); // * clipping factor here?
Canvas.SetLeft(l, point.X); // * clipping factor here?
MyCanvas.Children.Add(l);
EDIT: Further Clarification
Here's a concrete example of what I am trying to achieve. My image is an aerial photograph, and I want to mark a particular geographical feature (with, say, an ellipse.)
When the window is resized, the ellipse doesn't stay on the feature, it stays relative to the left and top of the canvas.
I can get it closer to the right place by moving it using a factor (newx = newheight/oldheight * oldx) but this doesn't quite work because of the UniformToFill stretch mode, which sees some of the image clipped off the canvas.
The Top and Left of the Canvas are 'anchored', while the Bottom and Right move when resizing... try setting the Canvas.Top Attached Property instead, along with the Canvas.Left Attached Property as you are:
var l = new Ellipse();
var scb = new SolidColorBrush();
scb.Color = Color.FromRgb(rCol, gCol, bCol);
l.Fill = scb;
l.StrokeThickness = 0;
l.Width = 3;
l.Height = 3;
Canvas.SetTop(l, point.Y); // * clipping factor here?
Canvas.SetLeft(l, point.X); // * clipping factor here?
MyCanvas.Children.Add(l);
UPDATE >>>
You asked Or is there a better way of fixing the location of a shape relative to the background image?
I answered this question, so I don't understand why you would need to do anything else... your objects will not move when the screen in resized *if you only set the Grid.Top and Grid.Left properties.
Im working on flowchart kind of application in asp.net using silverlight.. Im a beginner in Silvelight, Creating the elements (Rectangle,Ellipse,Line.. ) dynamically using SHAPE and LINE Objects in codebehind (c#)
These shapes will be generated dynamically, meaning I'll be calling a Web service on the backend to determine how many objects/shapes need to be created. Once this is determined, I'll need to have the objects/shapes connected together.
how to connect dynamically created shapes with a line in Silverlight like a flowchart.
I read the below article, but its not working for me, actualHeight & actualWidth of shapes values are 0.
Connecting two shapes together, Silverlight 2
here is my MainPage.xaml
<UserControl x:Class="LightTest1.MainPage">
<Canvas x:Name="LayoutRoot" Background="White">
<Canvas x:Name="MyCanvas" Background="Red"></Canvas>
<Button x:Name="btnPush" Content="AddRectangle" Height="20" Width="80" Margin="12,268,348,12" Click="btnPush_Click"></Button>
</Canvas>
code behind MainPage.xaml.cs
StackPanel sp1 = new StackPanel();
public MainPage()
{
InitializeComponent();
sp1.Orientation = Orientation.Vertical;
MyCanvas.Children.Add(sp1);
}
Rectangle rect1;
Rectangle rect2;
Line line1;
private void btnPush_Click(object sender, RoutedEventArgs e)
{
rect1 = new Rectangle()
{
Height = 30,
Width = 30,
StrokeThickness = 3,
Stroke = new SolidColorBrush(Colors.Red),
};
sp1.Children.Add(rect1);
rect2 = new Rectangle()
{
Height = 30,
Width = 30,
StrokeThickness = 3,
Stroke = new SolidColorBrush(Colors.Red),
};
sp1.Children.Add(rect2);
connectShapes(rect1, rect2);
}
private void connectShapes(Shape s1, Shape s2)
{
var transform1 = s1.TransformToVisual(s1.Parent as UIElement);
var transform2 = s2.TransformToVisual(s2.Parent as UIElement);
var lineGeometry = new LineGeometry()
{
StartPoint = transform1.Transform(new Point(1, s1.ActualHeight / 2.0)),
EndPoint = transform2.Transform(new Point(s2.ActualWidth, s2.ActualHeight / 2.0))
};
var path = new Path()
{
Data = lineGeometry,
Stroke = new SolidColorBrush(Colors.Green),
};
sp1.Children.Add(path);
}
what I am doing in button click event is just adding two rectangle shapes and tring to connect them with a line (like flowchart).
Please suggest what is wrong in my code..
Try replacing the line
connectShapes(rect1, rect2);
with
Dispatcher.BeginInvoke(() => connectShapes(rect1, rect2));
I'm not sure of the exact reason why this works, but I believe the shapes are only rendered once control passes out of your code, and only once they are rendered do the ActualWidth and ActualHeight properties have a useful value. Calling Dispatcher.BeginInvoke calls your code a short time later; in fact, you may notice the lines being drawn slightly after the rectangles.
The TransformToVisual method behaves in much the same way as the ActualWidth and ActualHeight properties. It will return an identity transformation if the shape hasn't been rendered. Even if your lines were being drawn with a definite width and height, they would end up being drawn all on top of one another at the top-left.
I also found that I needed to add the lines to the Canvas, not the StackPanel, in order for them to be drawn over the rectangles. Otherwise the StackPanel quickly filled up with lines with a lot of space above them.
I suppose it's some king of gradient used, but I can't tell.
I'd like to use the same in my WinForms application.
Easiest way to do something like this is to use a program like Paint.Net to get the RGB values of the colors used in the drawing.
Using a panel as an example:
void panel1_Paint(object sender, PaintEventArgs e) {
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
using (LinearGradientBrush br = new LinearGradientBrush(
panel1.ClientRectangle,
Color.FromArgb(52, 151, 254),
Color.FromArgb(61, 129, 243),
LinearGradientMode.Vertical)) {
e.Graphics.FillRectangle(br, panel1.ClientRectangle);
}
using (Pen p = new Pen(Color.FromArgb(37, 110, 184), 2)) {
e.Graphics.DrawRectangle(p, 0, 0,
panel1.ClientSize.Width - 1,
panel1.ClientSize.Height - 1);
}
}
Results in:
Pretty close to the original. You can make adjustments by lightening or darkening the colors used.